Boston Mk III

Cruiser Mk III

The Tank, Cruiser, Mk III (A13) was a Britishcruiser tank of World War II. It was the first British cruiser tank to use the Christie suspension system which gave higher speeds and better cross-country performance, previous models of cruiser tanks having used triple wheeled bogie suspension.

Design and development

Orders for the Mk I and Mk II Cruiser tanks were restricted, since the British Army had decided to produce a more advanced and faster cruiser tank which would incorporate the Christie suspension designed by American inventor J. Walter Christie and have better armor. In 1936, General Martel, a pioneer in tank design who had published works on armored warfare and pioneered the lightly armoured "tankette" to enhance infantry mobility, became assistant director of mechanization at the War Office. Earlier that year Martel had witnessed demonstrations of Soviet tank designs including the BT tank, which had been influenced by Christie's work. He urged the adoption of a tank that would use the suspension system and also follow Christie's practice of using a lightweight aircraft engine such as the Liberty Engine. The government authorized purchase and licencing of a Christie design via the Morris Motors Group.

The vehicle obtained from Christie became the basis of the Cruiser Mk III (A13). Following testing of two prototypes, the A13 was ordered into production and a total of 65 were manufactured. The Mk III weighed , had a crew of 4, a 340 hp engine which gave a top speed of and was armed with a 2 pounder gun and a machine gun. However, when it was introduced into service in 1937, the Army still lacked a formal tank division.

Like most British cruisers, the A 13 was fast but under-armoured. Most were lost in the French campaign in 1940, but a few were used in Greece and the North African campaign in 1940-41. The basic design was used for the Cruiser Mk IV.